Effect of microwave pretreatment on pyrolysis of chili straw: thermodynamics, activation energy, and solid reaction mechanism.

In this work, chili straw (CS) was pretreated by microwave at 250 W, 406 W, 567 W, and 700 W. The pyrolysis characteristics, kinetics, thermodynamic parameters, and solid reaction mechanism were investigated. The maximum weight loss rate increases from - 24.72%/°C at P0 to - 28.01%/°C at P700 after microwave pretreatment, and the residual mass decreases from 31.81 at P0 to 26.71% at P700. In addition, microwave pretreatment leads to a decrease in activation energy, ∆H, and ∆G at the end of the pyrolysis (α > 0.7). The solid reaction mechanism of CS pyrolysis is revealed by the Z-master plots method, with un-pretreated CS conforming to P2, D4, F3/2, and F3, respectively. Microwave pretreatment changes the solid reaction mechanism mainly in the third stage, when α = 0.8, the mechanism function changes from f(α) = (1 - α)3 at P0 to f(α) = (1 - α) at P700, and the number of reaction order is reduced, which is profitable for CS pyrolysis.

Low-cost pyrolysis of biomass-derived nitrogen-doped porous carbon: Chlorella vulgaris replaces melamine as a nitrogen source.

Porous carbon generated from biomass has a rich pore structure, is inexpensive, and has a lot of promise for use as a carbon material for energy storage devices. In this work, nitrogen-doped porous carbon was prepared by co-pyrolysis using bagasse as the precursor and chlorella as the nitrogen source. ZnCl2 acts as both an activator and a nitrogen fixer during activation to generate pores and reduce nitrogen loss. The thermal weight loss experiments showed that the pyrolysis temperatures of bagasse and chlorella overlap, which created the possibility for the synthesis of nitrogen-rich biochar. The optimum sample (ZBC@C-5) possessed a surface area of 1508 m2g-1 with abundant nitrogen-containing functional groups. ZBC@C-5 in the three-electrode system exhibited 244.1F/g at 0.5A/g, which was extremely close to ZBC@M made with melamine as the nitrogen source. This provides new opportunities for the use of low-cost nitrogen sources. Furthermore, the devices exhibit better voltage retention (39%) and capacitance retention (96.3%). The goal of this research is to find a low cost, and effective method for creating nitrogen-doped porous carbon materials with better electrochemical performance for highly valuable applications using bagasse and chlorella.

Preparation of high-value porous carbon by microwave treatment of chili straw pyrolysis residue.

Microwave technology is utilized to prepare porous carbon from the chili straw pyrolysis residue in this study. As the pyrolysis temperature increases, the thermal stability of biochar is higher. The carbon speciation of the porous carbon PC500 is closest to that of graphite, and its inorganic-C reaches to 51.21%. Notably, the specific surface area of the activated porous carbon increases with increasing pyrolysis temperature, with a maximum value of 2768.52 m2/g for PC500. Further testing of the electrochemical properties of the porous carbon, PC500 possesses a high specific capacitance of 352F/g at 1 A/g while that of conventional heating is only 226.1F/g. The porous carbon prepared by microwave heating has better electrical properties compared to conventional heating, and the biochar obtained at higher pyrolysis temperature has a richer pore structure after activation.

Catalytic co-pyrolysis of microwave pretreated chili straw and polypropylene to produce hydrocarbons-rich bio-oil.

In this work, the kinetic behavior and products of the co-pyrolysis of chili straw (CS) and polypropylene (PP) of distinguishing conditions (blending ratios, addition of catalysts, and microwave pretreatment at different power) had been investigated. Co-pyrolysis effectively reduced the proportion of oxygenated composition in CS, and the Oxygenated composition of 5CS5PP decreased by 76.69% compared to CS. When HZSM-5 was added, the aromatic hydrocarbons in the product increased from 4.46% to 17.34%, and the final residual mass decreased from 12.75% to 7.71%, illustrating that HZSM-5 had a positive effect on co-pyrolysis. Compared with P0HZSM-5, the microwave pretreatment at a higher power level of 567 W reduced the oxygenated composition from 17.41% to 13.09%, and the weight loss peak in the first stage increased from -18.11%/min to -19.94%/min. At the same time, the activation energy decreased from 271.25 kJ/mol to 231.13 kJ/mol.

Catalytic co-pyrolysis behaviors and kinetics of camellia shell and take-out solid waste using pyrolyzer - gas chromatography/mass spectrometry and thermogravimetric analyzer.

The influences of operating temperature, catalyst types and mixing ratios on co-pyrolysis of camellia shell (CS) and take-out solid waste (TSW) were investigated through orthogonal experiments design. The target was to gain more aliphatic hydrocarbons and monocyclic aromatic hydrocarbons (MAHs) and reduce the production of acids. According to orthogonal experiments results, higher temperature contributed to generate aliphatic hydrocarbons and inhibit formation of acids. Combined utilization of HZSM-5 and CaO was effective to obtain more MAHs and reduce acids. With the improvement of proportion of TSW, the yield of aliphatic hydrocarbons increased and acids decreased. The mixing ratio of CS and TSW was 3:7, 700 °C was chosen as operating temperature and combined utilization of HZSM-5 and CaO were identified. The apparent activation energy (Eave) of CS, TSW and their blends were calculated. 3CS7TSW had the lowest Eave which were 165.33 kJ/mol (by OFW) and 163.14 kJ/mol (by KAS).

Thermogelling chitosan-based polymers for the treatment of oral mucosa ulcers.

Current treatments for oral mucosa-related ulcers use drugs to relieve pain and promote healing, but rarely consider drug resistance to bacterial infection in the microenvironment of the oral cavity or the prevention of bleeding from gingival mucosa ulcers. We herein report an injectable, thermogelling chitosan-based system to address these concerns. An aqueous solution of chitosan-based conjugates (chitosan-g-poly(N-isopropylacrylamide) [CS-g-PNIPAAM] including 1a [CS-g-PNIPAAM with less PNIPAAM] and 1b [CS-g-PNIPAAM with more PNIPAAM], and chitosan-g-poly(N-isopropylacrylamide)-g-polyacrylamide [CS-g-PNIPAAM-g-PAM] 3) could reversibly form semi-solid gels at physiological temperatures for easy application to oral cavity ulcer sites by injection. The chitosan-based conjugate thermogels prepared could inhibit both Gram-positive and Gram-negative bacteria and the two with higher chitosan and poly(N-isopropylacrylamide) contents (1a and 1b) promoted proliferation of gingival fibroblasts in vitro. These two thermogels also exhibited improved blood clotting in an in vivo rat study. Thermogels 1a and 1b effectively promoted ulcer healing and shortened ulcer healing times in an oral gingival mucosa ulcer model using Sprague Dawley (SD) rats. These thermogels showed no obvious toxicity to the main organs of SD rats undergoing gingival ulcer treatment. These results suggest that this antibacterial biomaterial could be a promising injectable therapeutic agent for the treatment for oral mucosa ulcers.

The Anti-Inflammatory Effects of a Yin Zhi Huang Soup in an Experimental Autoimmune Prostatitis Rat Model.

The present study aimed to investigate the therapeutic effects of the Chinese herbal medicine Yin Zhi Huang soup (YZS) in an experimental autoimmune prostatitis (EAP) rat model. In total, 48 rats were randomly divided into the following four groups (n = 12/group): saline group, pathological model group, Qianlietai group, and YZS group. We determined the average wet weight of the prostate tissue, the ratio of the wet weight of the prostate tissue to body weight, tumor necrosis factor-alpha (TNF-α) levels in the blood serum, the expression of inducible nitric oxide synthase (iNOS) in the rats' prostate tissues, and the pathological changes in the prostate tissue using light microscopy. YZS reduced the rats' prostate wet weight, the ratio of the prostate wet weight to body weight, and TNF-α levels in the blood serum and inhibited the expression of iNOS in the rats' prostate tissues (P < 0.05). Following YZS treatment, the pathological changes in the rats' prostates were improved compared with those in the model group (P < 0.05). Furthermore, YZS treatment reduced inflammatory changes in the prostate tissue. It also significantly suppressed proinflammatory cytokines, such as TNF-α, and chemokines, such as iNOS, in the rat model of EAP.